Phytoremediation efficiency: assessment of flow system and plant performance in constructed wetland

Water is one of the most basic human needs for survival, though, there is a shortage in the amount of drinking water around the globe. Thus, preserving the quality of available water should be of high importance for us. For this purpose, we must treat water, used in every aspect of human activity, before releasing it back to the water bodies. With an increased inclination towards sustainability and green technologies, Constructed Wetlands (CW) are getting more attention as a more eco-friendly treatment for wastewater rather than conventional treatment plants. There are different types of CW operating around the world with a different typology of plants vegetated in them. The aim of this Thesis is to compare these differences to find the best combination for improving CW performance for wastewater treatment. Different case studies throughout Italy have been examined for this matter. Many of these cases, used Hybrid CW rather than a single stage of either Vertical Subsurface Flow CW (VSSF) or Horizontal Subsurface Flow CW (HSSF), and usually, there is a Floating Treatment Wetland (FTW) as a tertiary step for further refining water quality before releasing it. This kind of Treatment setup for CWs shows an increased abatement efficiency for wastewater. Lastly, vegetations in CW usually improve the efficiency of wetland performance. The important parameters in selecting macrophytes are their survivability and adaptability in wetland conditions. Among the macrophytes encountered Phragmites Australis and Iris Pseudacorus generally showed a higher growth performance and more adaptability in CW conditions.